Venetian blind tilter construction



Feb. 25, 1964 H. NELSON VENETIAN BLIND TILTER CONSTRUCTION Filed Aug. 21. 1961 United States Patent 3,122,198 VERETIAN BLEND TILTER CONSTRUCTION Harry Nelson, St. Louis, Mo., assignor to Artcraft Venetian Blind Manufacturing Company of St. Louis, St. Louis, Mo., a corporation of Missouri Filed Aug. 21, 1961, Ser. No. 132,894 1 Claim. (1. 160-176) This invention relates to a Venetian blind mechanism and particularly to the construction of apparatus for tilt ing the slats of a Venetian blind.

The slat tilting mechanism of this invention may be incorporated into any conventional Venetian blind of the type having separate pull cords or other means for raising and lowering the slats and having tapes or cords for supporting the slats. This slat tilting mechanism is provided in an assembly that can be incorporated directly into the housing structure to tilt the slats of one of these Venetian blinds.

The tilting assembly includes a bracket that supports a pulley and worm interconnected by a shaft and a gear that is rotated by the worm when the pulley is rotated. The gear has a fiat side that allows it to be keyed to a shaft which, in turn, is connected to the tapes or cords that support the slats, so that rotation of the shaft in opposite directions tilts the slats in opposite directions.

In this slat tilting assembly, the pulley, the worm, and the shaft interconnecting them are all molded together as a single part, and this single part is made of plastic or other synthetic material. Likewise, the worm gear is molded of plastic or nylon. Consequently, these parts are considerably less expensive than their metal counterparts, and the integral formation of the pulley, the worm and the interconnecting shaft provides a positive driving connection between the pulley and the worm that makes their formation of plastic feasible.

It is, therefore, a principal object of this invention to provide a slat tilting assembly for a Venetian blind having a pulley, a worm and an interconnecting shaft integrally molded as one plastic part, and another object is to provide a plastic worm gear that is driven by the worm.

Another object of the invention is to provide a bracket for supporting the pulley, worm, and worm gear that is so formed that damage to the parts is prevented. Specifically, it is an object to provide such a bracket wherein appropriate stops are provided to limit the sliding or bending of the pulley and worm to such an extent that they might be damaged.

Another object of the invention is to provide a bracket for a slat tilting mechanism that has a pulley about which a pullcord is wound, wherein the bracket has guides for the parts of the pullcord that depend from the pulley.

Gther objects and advantages will be apparent to those skilled in the art.

in the drawing:

FIGURE 1 is a front elevation view of the slat tilting mechanism of this invention with the Venetian blind housing shown in section;

PTGURE 2 is a right side elevation view in section taken along the line 22 of FIGURE 1;

FIGURE 3 is a top View in section taken along the line 33 of FIGURE 1;

FIGURE 4 is a left side elevation view in section taken along the line 'iof FIGURE 1;

FIGURE 5 is a view in section on an enlarged scale taken along the line 5-5 of FIGURE 1; and

FIGURE. 6 is an enlarged front elevation view of the portion of the mounting bracket that supports the slat ng mechanism.

Referring now to the drawing, a Venetian blind housltl having top, rear and bottom walls 11, 12 and i3 7 3,122,198 Patented Feb. 25, 1954 respectively, and an end cap 14, is mounted to a suppor ing structure 15. A bracket assembly 16 is supported by the housing 10 and, in turn, has flanges 17 with openings 18 therethrough for supporting the end of a rod 19. The rod 19 is conventional in the art and is connected to the tapes or cords that support a plurality of slats in such a way that, when the rod l9vis rotated in opposite directions, the slats will be tilted in opposite directions. The rod 19 has a fiat side 2%.

The bracket 16 has an end wall 23 that has a hole 24 through it to receive the end of the rod 19. A flange 25 is bent upwardly and spaced from the wall 23 to operate as an end stop for the rod 19.

A plate 26 is fastened to the end wall 23 by bent tabs 27. The plate 26 has a side 28 that is spaced from the wall 23. There is a hole 29 through the plate 28 coaxial with the hole 24 and surrounded by an annular flange 3% A plastic worm gear 31 is positioned between the waH 23 and the plate 26. The gear 31 has a cylindrical boss 32 that projects into the hole 29 so that the flange 3% can guide the gear 31 in its rotational position.

There is a hole 34 through the gear 31 and the boss 32. The hole 34 has a fiat side 35. The rod 19 passes through the hole 34, and the flat side 2% of the rod cooperates with the fiat side 35 of the hole 34 to prevent relative rotation between the gear 31 and the rod 19. As can be seen in FIGURE 5, the gear 31 has teeth 36 that extend only part of the Way around the gear to prevent damage to the mechanism as will be described.

The end wall 23 has a hole 49 in it from which the flange 25 aforementioned is formed. On opposite sides of the hole -tl the end wall 23 is bent to form two recesses 41 that are aligned. The plate 26 has a hole 42 through it opposite the hole 49, and has a pair of bent flanges 43 on opposite sides of the hole 42. The flanges .3 cooperate with the recesses 41 to define a cylindrical journal for the shaft There is a worm 46 intermediate of the ends of the shaft 45 and a pulley 47 at the front end of the shaft 45. The shaft 45, the Worm 46 and the pulley 47 are all integrally molded as a single plastic part. The worm 46 is positioned within the holes 4s and 42, and the bent flanges 4-1 are flared outwardly to provide stops 48 on opposite sides of the worm. These stops 48 limit the sliding movement of the worm and shaft and also eliminate contact by the worm 4&5 with sharp edges on the bracket.

A cord 5% is wrapped around the pulley 4'7 with its parts 51 and 52 hanging below the pulley. When one of these cord parts 51 or 52 is pulled, the pulley 47 is rotated and its integral shaft 45 and worm 46 rotate with it. This action rotates the worm gear 31 and the rod 19 to pivot the blind slats.

The bracket i6 is formed with a pair of spaced bent loops 53 and 5 that are positioned beneath the pulley 47 and inwardly of its outer diameter. The cord parts 51 and 52 pass through these loops 53 and 54, and the loops guide the direction of the cord parts. The loops 53 and 54 prevent the cord from escaping from the groove of the pulley 47 and also prevent either of the cord parts from rotating too far with the pulley into a position of interference with the other cord part.

The bracket is has a tab or lug 55 that is bent downwardly and outwardly beneath the pulley 37. This lug 55 is spaced only slightly below the pulley 47 and operates as a stop should too great a force be exerted upon the pulley 4? by the cords 51 or 52 tending to bend the shaft 45. Thus the lug 55 protects the molded assembly that includes the shaft 45, the worm 46 and the pulley 1-7 against damage and breakage.

The teeth of the gear extend only partly around the gear. Therefore, the gear rotates out of mesh with the Worm when the Worm is turned further than necessary to tilt the slats fully. This formation of the gear prevents damage to the shaft 43 from twisting or rotational shear.

Various changes and modifications may be made within the process of this invention as will be readily apparent to those skilled in the art. Such changes and modifications are within the scope and teaching of this invention as defined by the claim appended hereto.

What is claimed is:

In a Venetian blind having a plurality of slats suspended from a mounting member by tapes or cords arranged in pairs on opposite sides or the slats, a plate supported by the mounting member, a rod rotatably supported by the plate for pivoting the slats in opposite directions upon rotation of the rod in opposite directions, a molded plastic gear connected to the rod, a shaft rotatably supported by the plate opposite the gear and having References Cited in the file of this patent UNITED STATES PATENTS 2,222,226 Haase Nov. 19, 1940 2,580,479 Stogran Jan. 1, 1952 2,630,861 Nelson Mar. 10, 1953 2,809,531 Moyer Oct. 15, 1957 

